What organisers believe will be the biggest single literary event in history is to raise the curtain on next month's World Book Night, itself billed as "the biggest book give-away ever". On 4 March London's Trafalgar Square will be given over to a "glittering celebration of the written word", with 10,000 people expected to attend.

The free event will feature appearances from numerous celebrated authors, ranging from Alan Bennett to Nick Cave, reading from their favourite books.

Margaret Atwood, who will be visiting London for the occasion, said the event would be five times larger than the biggest public reading she has given hitherto. She said she was "looking forward very much [to] an astounding event pulled off in short space!", praising the organisers for pulling the whole event together in little more than six months.

Canongate publisher Jamie Byng, who is chairing the event, said: "We felt that it was appropriate to launch World Book Night with a suitably ambitious event that celebrates on a large scale writing, reading and the shared experience that books can provide. This occasion in Trafalgar Square should deliver exactly that and is a memorable way of bringing thousands of the givers together."

Half the tickets have been reserved for the 20,000 volunteers who have signed up to hand out 48 free copies of a favourite book the following evening, but the rest will be available to members of the public who turn up for the extravaganza, to be hosted by TV presenter Graham Norton.

World Book Night was inspired by the success of World Book Day, which last year distributed tokens to schoolchildren for 600,000 specially printed books. With each of the volunteers set to give away 48 books, and another 40,000 to be distributed by the organisers, a million books in total will be given away on 5 March. The event has already attracted endorsements from many of the biggest names in print, including Alan Bennett, John le Carré and Mark Haddon, all of whom are scheduled to appear at the Trafalgar Square reading. The other authors scheduled so far are Edna O'Brien, DBC Pierre, Philip Pullman, Lemn Sissay and Derek Walcott.

Organisers say the Trafalgar Square event will be followed by hundreds of events around the UK on World Book Night itself, details of which can be found on its website.

Boris Johnson, the mayor of London, welcomed the plans, saying: "The ability to put pen to paper has given us the glorious capacity to share experience, history and knowledge – and one of life's greatest pleasures, which is to read a book." He added that he hoped World Book Night "will stimulate latent as well as avid readers".